There is a need for a systematic approach to identify and describe genetically determined eye disorders in mice. Our preliminary screening of mouse colonies, strains, and mutant stocks at the Jackson Laboratory (JAX) using modified clinical techniques which screen for most common human ocular disorders revealed a large number of mouse ocular abnormalities heretofore not known or well characterized. Since there is a high genetic homology between mouse and human genome, ascertainment, characterization, and gene mapping in mouse eye disorders is likely to lead to a definition of large numbers of mouse models of human ocular diseases. Since only a portion of the JAX stocks have been evaluated, it is expected there will be a large number of additional ocular disorders found. The methodology calls for a true partnership between a clinician/ophthalmologist and mouse geneticist/mapping expert. The protocol includes the initial and continual screening of a large number of strains and mutants from JAX stocks by biomicroscopy and indirect ophthalmoscopy. Along with clinical characterization of the disorder, studies of genetic etiology and mapping of Mendelian disorders will be done. The uniqueness of each disorder will be confirmed by breeding experiments and linkage analysis; the latter technique will also map the disorder to a specific chromosomal site which will allow for comparative mapping between man and mouse for these conditions. Early publications of findings will be made so that the disorders are known and made available immediately to the scientific community. Further indepth studies will be done in our laboratories specifically on retinal disorders.